Basic notes on BGP (border gateway protocol)

by Shabeer ibm

BGP

RIP, OSPF and EIGRP are all different but they have one thing in common…they want to find
the shortest path to the destination. But when coming to Internet being able to manipulate traffic paths is far more important than finding the shortest path. There is only one routing protocol we currently use on the Internet which is BGP.

Within an autonomous system we use an IGP like OSPF or EIGRP. For routing between the different autonomous systems we use an EGP (external gateway protocol). The only EGP we use nowadays is BGP. We can say internet as a bunch of autonomous system that are connected to each other.We need to register AS number for BGP just like public IP address.Autonomous system numbers are 16-bit which means we have AS from 1 up to 65535. There’s also a private range (64512 – 65535) which we can use for non-internet usage

There are two types of BGPExternal BGP: Used for routing between autonomous systemsInternal BGP: Used for routing within the autonomous system.

Points to Remember

BGP is the routing protocol we use to route between autonomous systems: